(→‎That bq27000 chip seems to be pretty cool, how can i read and understand its raw registers?: added mirror location that also has further goodies)

(31 intermediate revisions by 8 users not shown)

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NB: Some of the described behaviour depends on the kernel, the

NB: Some of the described behaviour depends on the kernel, the

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relevant code was pushed on 02 Aug to andy-tracking

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relevant code was pushed on 2009-08-02 to andy-tracking. Some older kernel versions may have quite nasty hacks ('reenabling MBC though battery reports full') that seriously wreck your battery within months.

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== Battery care and safety guidelines ==

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=== How can I break my battery? ===

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To successfully kill your LiIon battery without applying brute force, you simply may disobey any of the following advices:

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==== Temperature ====

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Never expose or let warm up battery to high temperatures. 70°C might be a limit for safe operation, and >100°C most likely is a killer for the cell. This is especially true during charge/discharge.

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==== Drop ====

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Never let the battery drop on a hard surface or by any other means expose to hard impact.

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==== Wrong storage ====

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LiIon cells don't like to be kept at any extreme for a prolonged time. So *never* store away your device with battery inserted, for a period longer than a few days. Charge battery to a reasonable level prior to extended periods of no usage.

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Do not store battery in charger, as this may cause a permanent charging level of 100% which is as deteriorating to the LiIon cell chemistry as is storage at 0%. Keeping battery in Neo which is powered by external source is safe though, even for months, as the Neo's PMU charger circuit takes care to treat the battery nicely.

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Also see [http://wiki.openmoko.org/wiki/Battery_Questions_and_Answers#I_have_several_compatible_batteries._What_are_the_storage_requirements_for_them.3F Storage]

=== What are hardware capabilities of gta01 and gta02 with regard to battery management? ===

=== What are hardware capabilities of gta01 and gta02 with regard to battery management? ===

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=== I have several compatible batteries. What are the storage requirements for them? ===

=== I have several compatible batteries. What are the storage requirements for them? ===

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Keep in a dry cool place charged to no more than 75%.

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Keep in a dry cool place charged to no more than 75% and NEVER under 25%. Check every 3 months and recharge when due, cells will self-discharge over time and once they reach 0% level they are dead within weeks!

=== That bq27000 chip seems to be pretty cool, how can i read and understand its raw registers? ===

=== That bq27000 chip seems to be pretty cool, how can i read and understand its raw registers? ===

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[[User:jOERG|DocScrutinizer]] to the rescue! Here's his magic script to do that: [http://people.openmoko.org/joerg/battery/bq27k-detail].

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[[User:jOERG|DocScrutinizer]] to the rescue! Here's his magic script to do that: [http://people.openmoko.org/joerg/battery/bq27k-detail2]. Also see [http://maemo.cloud-7.de/maemo5/usr/local/sbin/] and [http://maemo.cloud-7.de/maemo5/patches_n_tools/]

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== Safety issues ==

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== Safety considerations in detail ==

=== Do OM devices control temperature to stop charging if the battery gets too hot? ===

=== Do OM devices control temperature to stop charging if the battery gets too hot? ===

Depending on various factors (GPRS activated, number of cells to observe, band...) the modem may consume an average standby current of 4mA up to >30mA while registered to a network. For normal (AT%SLEEP=2) situation the standby current is ~15mA. So *usually* the charge end detection should work.

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Anyway even if the above mentioned charge end threshold never is reached, the PMU stops charging of bat after expire of some emergency cutoff timer (some hours)

=== Does it mean if i leave my phone plugged it will eventually fully discharge the battery? ===

=== Does it mean if i leave my phone plugged it will eventually fully discharge the battery? ===

On gta02 the charger will restart the charge automatically once the

On gta02 the charger will restart the charge automatically once the

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battery voltage reaches ~4V which corresponds to ~76%. Not sure about

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battery voltage reaches ~4V which corresponds to ~76% (If PMU MBC is configured by kernel to enable auto-resume). Not sure about

gta01, requires more investigation. :-/

gta01, requires more investigation. :-/

=== Ok, how to make sure my battery is fully charged before a long trip? ===

=== Ok, how to make sure my battery is fully charged before a long trip? ===

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Replug the charger, it will trigger charging no matter what the

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Replug the charger at least 90 minutes before you need full battery, it will trigger charging no matter what the

current capacity is.

current capacity is.

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mangling of "status" sysfs node before presenting it to the user. If

mangling of "status" sysfs node before presenting it to the user. If

you want to make a decent bugreport please add clear steps to

you want to make a decent bugreport please add clear steps to

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reproduce and <code>/sys/class/power_supply/battery/uevent</code> contents for all

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reproduce and

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<code>

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cat /sys/class/power_supply/battery/uevent

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cat /sys/class/i2c-adapter/i2c-0/0-0073/gta01_battery/uevent

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</code>

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contents for all

relevant states.

relevant states.

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Then you load the dumb battery driver:

Then you load the dumb battery driver:

modprobe gta01_battery

modprobe gta01_battery

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Since kernel 2.6.34 the module is called platform-battery

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If you need to use bq27000 driver again, do:

If you need to use bq27000 driver again, do:

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[[User:jOERG|Joerg Reisenweber]]

[[User:jOERG|Joerg Reisenweber]]

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[[Category:Battery]]

[[Category:Neo_FreeRunner_Hardware]]

[[Category:Neo_FreeRunner_Hardware]]

[[Category:Neo1973_Hardware]]

[[Category:Neo1973_Hardware]]

Latest revision as of 14:40, 5 August 2013

NB: Some of the described behaviour depends on the kernel, the
relevant code was pushed on 2009-08-02 to andy-tracking. Some older kernel versions may have quite nasty hacks ('reenabling MBC though battery reports full') that seriously wreck your battery within months.

LiIon cells don't like to be kept at any extreme for a prolonged time. So *never* store away your device with battery inserted, for a period longer than a few days. Charge battery to a reasonable level prior to extended periods of no usage.
Do not store battery in charger, as this may cause a permanent charging level of 100% which is as deteriorating to the LiIon cell chemistry as is storage at 0%. Keeping battery in Neo which is powered by external source is safe though, even for months, as the Neo's PMU charger circuit takes care to treat the battery nicely.

gta02 - accurate and sophisticated reporting of capacity,
time_to_full, time_to_empty, temperature and battery current during
both charge and discharge thanks to bq27000 (aka Coulomb Counter). More details at Neo FreeRunner Battery.

[edit] What are hardware capabilities of gta01 and gta02 with regard to battery management?

gta01: charging all battery types, measuring temperature with
battery-integrated thermistor (currently charging and measuring
temperature for non-gta01 batteries doesn't work due to the kernel
driver issues but it's software limitation), measuring battery output
voltage, very inaccurate and noisy measuring of battery current

gta01 and gta02 batteries will fit wherever BL-6C fits but they
can't be charged in nokia phones unless you isolate the middle pin
from the battery and connect a resistor of ~50k (actual measured value
on a cold (25C) battery is 75k, on a slightly warm battery - 82k) from
it to the ground (to fake a thermistor presence).

The "good" ones will most probably require the same trick needed
for nokia phones. More cheaper ones are more likely to ignore
thermistor absence.

[edit] I have several compatible batteries. What are the storage requirements for them?

Keep in a dry cool place charged to no more than 75% and NEVER under 25%. Check every 3 months and recharge when due, cells will self-discharge over time and once they reach 0% level they are dead within weeks!

[edit] That bq27000 chip seems to be pretty cool, how can i read and understand its raw registers?

[edit] Do OM devices control temperature to stop charging if the battery gets too hot?

No, since all batteries (not raw cells!) have an integrated
protection circuits.

[edit] Can i use that fancy 2800 mAh BL-5C-compatible battery i saw on ebay?

Unless you want an explosion in your pocket i wouldn't recommend
using any battery that is not produced by a reputable vendor and
widely tested. And even reputable vendors make mistakes, nokia once
had to recall 46 million batteries manufactured by Matsushita ([4]).

[edit] You say that BL-5C is compatible with my gta02. Does that mean i can use that BL-5C-compatible bat i bought for a buck from a bum?

The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold setting of PMU charger is
about 16mA, the latest Qi increases the threshold to ~32mA.

Depending on various factors (GPRS activated, number of cells to observe, band...) the modem may consume an average standby current of 4mA up to >30mA while registered to a network. For normal (AT%SLEEP=2) situation the standby current is ~15mA. So *usually* the charge end detection should work.

Anyway even if the above mentioned charge end threshold never is reached, the PMU stops charging of bat after expire of some emergency cutoff timer (some hours)

[edit] Does it mean if i leave my phone plugged it will eventually fully discharge the battery?

On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76% (If PMU MBC is configured by kernel to enable auto-resume). Not sure about
gta01, requires more investigation. :-/

[edit] Ok, how to make sure my battery is fully charged before a long trip?

Replug the charger at least 90 minutes before you need full battery, it will trigger charging no matter what the
current capacity is.

[edit] My power/aux LED indicates charging/discharging/whatever, what does that mean (aka why it's still blue even after i unplugged the charger)?

Ask FSO guys about it, some of them think that the user shouldn't
really know what's happening and therefore they do some special
mangling of "status" sysfs node before presenting it to the user. If
you want to make a decent bugreport please add clear steps to
reproduce and

Can nokia phones use/charge gta01/gta02 batteries?

gta01 and gta02 batteries will fit wherever BL-6C fits but they
can't be charged in nokia phones unless you isolate the middle pin
from the battery and connect a resistor of ~50k (actual measured value
on a cold (25C) battery is 75k, on a slightly warm battery - 82k) from
it to the ground (to fake a thermistor presence).

Can third-party chargers charge gta01/gta02 batteries?

The "good" ones will most probably require the same trick needed
for nokia phones. More cheaper ones are more likely to ignore
thermistor absence.

I have several compatible batteries. What are the storage requirements for them?

Keep in a dry cool place charged to no more than 75%.

That bq27000 chip seems to be pretty cool, how can i read and understand its raw registers?

Safety issues

Do OM devices control temperature to stop charging if the battery gets too hot?

No (probably gta01 does, need to check).

Isn't it dangerous?

No, since all batteries (not raw cells!) have an integrated
protection circuits.

Can i use that fancy 2800 mAh BL-5C-compatible battery i saw on ebay?

Unless you want an explosion in your pocket i wouldn't recommend
using any battery that is not produced by a reputable vendor and
widely tested. And even reputable vendors make mistakes, nokia once
had to recall 46 million batteries manufactured by Matsushita ([2]).

You say that BL-5C is compatible with my gta02. Does that mean i can use that BL-5C-compatible bat i bought for a buck from a bum?

You bet, go ahead.

Charging

My battery charges to 100% but then charging stops and the battery keeps discharging, wtf?

LiIon batteries don't like to be kept fully charged, so the charger
stops as soon as charging current becomes less than threshold. If you
have GSM on it will discharge the battery.

But why doesn't it ever stop charging on my device?

The GSM modem is connected directly to the battery terminals so if
it's active, charger will think it's still charging the battery and
won't turn off unless GSM becomes inactive. The default threshold is
about 16mA, the latest Qi increases the threshold to ~32mA.

Does it mean if i leave my phone plugged it will eventually fully discharge the battery?

On gta02 the charger will restart the charge automatically once the
battery voltage reaches ~4V which corresponds to ~76%. Not sure about
gta01, requires more investigation. :-/

Ok, how to make sure my battery is fully charged before a long trip?

Replug the charger, it will trigger charging no matter what the
current capacity is.

My power/aux LED indicates charging/discharging/whatever, what does that mean (aka why it's still blue even after i unplugged the charger)?

Ask FSO guys about it, some of them think that the user shouldn't
really know what's happening and therefore they do some special
mangling of "status" sysfs node before presenting it to the user. If
you want to make a decent bugreport please add clear steps to
reproduce and /sys/class/power_supply/battery/uevent contents for all
relevant states.